1// Ceres Solver - A fast non-linear least squares minimizer
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29// Author: sameeragarwal@google.com (Sameer Agarwal)
30
31#include "ceres/schur_ordering.h"
32
33#include <cstddef>
34#include <vector>
35#include "gtest/gtest.h"
36#include "ceres/collections_port.h"
37#include "ceres/graph.h"
38#include "ceres/problem_impl.h"
39#include "ceres/program.h"
40#include "ceres/stl_util.h"
41#include "ceres/cost_function.h"
42#include "ceres/internal/scoped_ptr.h"
43#include "ceres/sized_cost_function.h"
44
45namespace ceres {
46namespace internal {
47
48typedef Graph<ParameterBlock*> HessianGraph;
49typedef HashSet<ParameterBlock*> VertexSet;
50
51template <int M, int N1 = 0, int N2 = 0, int N3 = 0>
52class DummyCostFunction: public SizedCostFunction<M, N1, N2, N3> {
53  virtual bool Evaluate(double const* const* parameters,
54                        double* residuals,
55                        double** jacobians) const {
56    return true;
57  }
58};
59
60class SchurOrderingTest : public ::testing::Test {
61 protected :
62  virtual void SetUp() {
63    // The explicit calls to AddParameterBlock are necessary because
64    // the below tests depend on the specific numbering of the
65    // parameter blocks.
66    problem_.AddParameterBlock(x_, 3);
67    problem_.AddParameterBlock(y_, 4);
68    problem_.AddParameterBlock(z_, 5);
69    problem_.AddParameterBlock(w_, 6);
70
71    problem_.AddResidualBlock(new DummyCostFunction<2, 3>, NULL, x_);
72    problem_.AddResidualBlock(new DummyCostFunction<6, 5, 4>, NULL, z_, y_);
73    problem_.AddResidualBlock(new DummyCostFunction<3, 3, 5>, NULL, x_, z_);
74    problem_.AddResidualBlock(new DummyCostFunction<7, 5, 3>, NULL, z_, x_);
75    problem_.AddResidualBlock(new DummyCostFunction<1, 5, 3, 6>, NULL,
76                              z_, x_, w_);
77  }
78
79  ProblemImpl problem_;
80  double x_[3], y_[4], z_[5], w_[6];
81};
82
83TEST_F(SchurOrderingTest, NoFixed) {
84  const Program& program = problem_.program();
85  const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks();
86  scoped_ptr<HessianGraph> graph(CreateHessianGraph(program));
87
88  const VertexSet& vertices = graph->vertices();
89  EXPECT_EQ(vertices.size(), 4);
90
91  for (int i = 0; i < 4; ++i) {
92    EXPECT_TRUE(vertices.find(parameter_blocks[i]) != vertices.end());
93  }
94
95  {
96    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[0]);
97    EXPECT_EQ(neighbors.size(), 2);
98    EXPECT_TRUE(neighbors.find(parameter_blocks[2]) != neighbors.end());
99    EXPECT_TRUE(neighbors.find(parameter_blocks[3]) != neighbors.end());
100  }
101
102  {
103    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[1]);
104    EXPECT_EQ(neighbors.size(), 1);
105    EXPECT_TRUE(neighbors.find(parameter_blocks[2]) != neighbors.end());
106  }
107
108  {
109    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[2]);
110    EXPECT_EQ(neighbors.size(), 3);
111    EXPECT_TRUE(neighbors.find(parameter_blocks[0]) != neighbors.end());
112    EXPECT_TRUE(neighbors.find(parameter_blocks[1]) != neighbors.end());
113    EXPECT_TRUE(neighbors.find(parameter_blocks[3]) != neighbors.end());
114  }
115
116  {
117    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[3]);
118    EXPECT_EQ(neighbors.size(), 2);
119    EXPECT_TRUE(neighbors.find(parameter_blocks[0]) != neighbors.end());
120    EXPECT_TRUE(neighbors.find(parameter_blocks[2]) != neighbors.end());
121  }
122}
123
124TEST_F(SchurOrderingTest, AllFixed) {
125  problem_.SetParameterBlockConstant(x_);
126  problem_.SetParameterBlockConstant(y_);
127  problem_.SetParameterBlockConstant(z_);
128  problem_.SetParameterBlockConstant(w_);
129
130  const Program& program = problem_.program();
131  scoped_ptr<HessianGraph> graph(CreateHessianGraph(program));
132  EXPECT_EQ(graph->vertices().size(), 0);
133}
134
135TEST_F(SchurOrderingTest, OneFixed) {
136  problem_.SetParameterBlockConstant(x_);
137
138  const Program& program = problem_.program();
139  const vector<ParameterBlock*>& parameter_blocks = program.parameter_blocks();
140  scoped_ptr<HessianGraph> graph(CreateHessianGraph(program));
141
142  const VertexSet& vertices = graph->vertices();
143
144  EXPECT_EQ(vertices.size(), 3);
145  EXPECT_TRUE(vertices.find(parameter_blocks[0]) == vertices.end());
146
147  for (int i = 1; i < 3; ++i) {
148    EXPECT_TRUE(vertices.find(parameter_blocks[i]) != vertices.end());
149  }
150
151  {
152    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[1]);
153    EXPECT_EQ(neighbors.size(), 1);
154    EXPECT_TRUE(neighbors.find(parameter_blocks[2]) != neighbors.end());
155  }
156
157  {
158    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[2]);
159    EXPECT_EQ(neighbors.size(), 2);
160    EXPECT_TRUE(neighbors.find(parameter_blocks[1]) != neighbors.end());
161    EXPECT_TRUE(neighbors.find(parameter_blocks[3]) != neighbors.end());
162  }
163
164  {
165    const VertexSet& neighbors = graph->Neighbors(parameter_blocks[3]);
166    EXPECT_EQ(neighbors.size(), 1);
167    EXPECT_TRUE(neighbors.find(parameter_blocks[2]) != neighbors.end());
168  }
169
170  // The constant parameter block is at the end.
171  vector<ParameterBlock*> ordering;
172  ComputeSchurOrdering(program, &ordering);
173  EXPECT_EQ(ordering.back(), parameter_blocks[0]);
174}
175
176}  // namespace internal
177}  // namespace ceres
178